1. Field of the Invention
The present invention relates to a pitching rubber capable of resisting deformation during use and an overall configuration and composition that imparts strength to the pitching rubber. More particularly, included in embodiments of the invention is a pitching rubber which provides an all-in-one durable construction with improved performance characteristics over existing pitching rubbers.
2. Description of Related Art
Properly laid out and constructed baseball fields are paramount to the game. Baseball and softball are played on fields having a playing surface comprising both turf and exposed soil or “skinned” areas. Successful maintenance programs for such ball fields thus include highly detailed maintenance of the skinned areas as well as the turf. Due to diversity among infield soils, however, maintenance programs are not universal. As such, because the composition of the skinned portions of the field vary greatly from field to field, maintenance of the field in accordance with regulations for a particular type of ball game is complex.
Although the basic layout of a ball field for playing softball, major league baseball, minor league baseball, little league, pony league, or Babe Ruth league type games is relatively similar (very generally involving four bases and a pitching mound), regulations for each type of game specify particular dimensions for the placement of the bases, pitching mound, and sub-parts of the pitching mound or pitching area.
Routinely, an area of the field, which is particularly difficult to maintain according to regulations is the pitcher's mound. For major league baseball, the pitcher's mound “clay” has a diameter of 18 feet. Within the pitcher's mound is a pitching rubber or toe plate, which is disposed at an offset position within the 18-foot circle, that is 10 feet from the front (toward home plate) and 8 feet from the back of the circle. The dimensions of a standard pitching rubber are 24 inches long and 6 inches wide. Additionally, the distance from the pitching rubber to home plate must be 60 feet 6 inches. At the time of installing or replacing a pitching rubber, its placement must be precise in order to meet regulations for play.
The top of the pitching “mound” is actually a flat or plateau. This surface is 5 feet in diameter. The top of the plateau is 10 inches above the surface level of home plate. A field level is often used to ensure accuracy of the height of the mound. Building a pitcher's mound is an art and a science. With so many regulation parameters, it is not difficult to recognize that formation and maintenance of the pitcher's mound is one of the most common aspects for errors in preparing a baseball field.
Just as the relative placement of the pitcher's plate, pitcher's mound, home plate, and bases is critical, so is the composition of the soil used for the skinned portions of the field. Even further, the soil composition of the infield is selectively different from the composition of the earth surrounding and comprising the pitcher's mound. Indeed, a mix of materials is often used to build the pitcher's landing area. In particular, a significant concentration of clay is required to provide the necessary stability and durability of this play area due to the increased traffic it receives as compared with other non-turf portions of the field. For example, a composition comprising 40% sand, 20% silt, and 40% clay is often recommended, but can vary greatly from field to field.
The pitching rubber and area of the field in which it is located is one of the most difficult portions of the field and maintain in accordance with regulations. In accordance with the rules of the game, the pitcher must be in contact with the pitching rubber while throwing the baseball or softball. Therefore, the pitching rubber is subjected to a high degree of wear and tear, requiring frequent replacement. Further, for relatively thin pitching rubbers and because there is only a very limited surface against which the soles and spikes of the pitcher's shoes can engage during the pitching motion, soil in front of the pitching rubber may become displaced during a game and from game to game. A typical problem of commonly used pitching rubbers is that they buckle in the center due to a lack of strength and support from the surrounding earth making their replacement necessary.
Existing pitching rubbers include those that are rigidly secured to blocks of wood embedded in the mound area. Oftentimes, the pitching rubber is rigidly mounted in place by nailing the same to the wood blocks. In U.S. Pat. No. 5,919,103, a relatively thin pitching rubber is supported by a thin wood or metal platform which in turn is further supported by elongated members extending a length into the earth. However, the volume below the pitching rubber being the ground is of a different composition than the rubber and does not have the strength or resistance to deformation that a solid rubber pitching rubber would have to be able to withstand the normal wear and tear associated with the game over an extended period of time. Disadvantages of these types of pitching rubbers include that they may loosen after use and cause their placement within the pitcher's mound to fall outside of the regulation specifications, due to the combination of their rigidity and lack of a substantial depth of solid rubber material extending into the ground.
Various attempts have been made in the prior art to ameliorate some of the noted disadvantages. In U.S. Pat. No. 4,591,154, a pitching rubber is disclosed which is secured to the top of a hollow box intended to be filled with cement, rocks, or soil and inserted in the ground. Even with a cement filling, the product still fails to provide a long lasting solution. In such arrangement, the box embedded in the ground to which the pitching rubber is attached does not have the needed tensile strength, elongation, resilience, and compression characteristics to withstand wear and tear during maintenance or use.
Other pitching rubbers are hollow rubber cylinders with a block shape exterior and a cylindrical inner diameter. Such assemblies claim to provide the capability of rotating the block after the pitching rubber on the exposed surface wears out. This type of pitching rubber is constructed to be used up to four times. However, because the pitching rubber is not solid and does not have a density capable of resisting deformation, the pitching rubber will bow or buckle on one side leaving the other three pitching rubbers damaged as well and thus unusable. Further, because the hollow pitching rubber does not have a substantial front, back, and bottom support surface area supported by a sufficiently dense interior, tamping of the surrounding ground in which it is place will lead to further buckling of the pitching rubber. Recognizing this deficiency, such products have recently been offered with inserts to fill the void or support the interior structure within the pitching rubber. The inserts, however, are made aluminum or PVC tubes which do not have the same physical characteristics as the pitching rubber in which they are placed. In embodiments where the tubing is filled with material, the same problem is noted in that the filling material, whether clay or foam, is not of the same composition. These arrangements that are either not solid and/or do not provide a uniform density throughout the product continue to provide pitching rubber assemblies which are not satisfactorily stable and require more frequent maintenance attention. Accordingly, in order to achieve a hollow-core pitching rubber that is sufficiently strong, either a change in the configuration is needed (moving from hollow core to solid core, smaller hollow core, or semi-solid core), or a change in rubber material to complement the particular configuration is needed, or both.
With at least 70+ home games played in the major and minor leagues each season, and the need for groundskeepers to maintain the pitching mound to almost perfection, maintenance can be time consuming, laborious, and costly. Thus, there remains a need for an improved pitching rubber which is capable of withstanding more wear and tear and is easy to manufacture, install and replace.